On 8/22/24 1:38 AM, Steven Price wrote:
Query the RMI version number and check if it is a compatible version. A
static key is also provided to signal that a supported RMM is available.
Functions are provided to query if a VM or VCPU is a realm (or rec)
which currently will always return false.
Signed-off-by: Steven Price <steven.price@xxxxxxx>
---
Changes since v2:
* Drop return value from kvm_init_rme(), it was always 0.
* Rely on the RMM return value to identify whether the RSI ABI is
compatible.
---
arch/arm64/include/asm/kvm_emulate.h | 17 +++++++++
arch/arm64/include/asm/kvm_host.h | 4 ++
arch/arm64/include/asm/kvm_rme.h | 56 ++++++++++++++++++++++++++++
arch/arm64/include/asm/virt.h | 1 +
arch/arm64/kvm/Makefile | 3 +-
arch/arm64/kvm/arm.c | 6 +++
arch/arm64/kvm/rme.c | 50 +++++++++++++++++++++++++
7 files changed, 136 insertions(+), 1 deletion(-)
create mode 100644 arch/arm64/include/asm/kvm_rme.h
create mode 100644 arch/arm64/kvm/rme.c
[...]
diff --git a/arch/arm64/kvm/rme.c b/arch/arm64/kvm/rme.c
new file mode 100644
index 000000000000..418685fbf6ed
--- /dev/null
+++ b/arch/arm64/kvm/rme.c
@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2023 ARM Ltd.
+ */
+
+#include <linux/kvm_host.h>
+
+#include <asm/rmi_cmds.h>
+#include <asm/virt.h>
+
+static int rmi_check_version(void)
+{
+ struct arm_smccc_res res;
+ int version_major, version_minor;
+ unsigned long host_version = RMI_ABI_VERSION(RMI_ABI_MAJOR_VERSION,
+ RMI_ABI_MINOR_VERSION);
+
+ arm_smccc_1_1_invoke(SMC_RMI_VERSION, host_version, &res);
+
+ if (res.a0 == SMCCC_RET_NOT_SUPPORTED)
+ return -ENXIO;
+
+ version_major = RMI_ABI_VERSION_GET_MAJOR(res.a1);
+ version_minor = RMI_ABI_VERSION_GET_MINOR(res.a1);
+
+ if (res.a0 != RMI_SUCCESS) {
+ kvm_err("Unsupported RMI ABI (v%d.%d) host supports v%d.%d\n",
+ version_major, version_minor,
+ RMI_ABI_MAJOR_VERSION,
+ RMI_ABI_MINOR_VERSION);
This message is perhaps something like below since a range of versions can be
supported by one particular RMM release.
kvm_err("Unsupported RMI ABI v%d.%d. Host supports v%ld.%ld - v%ld.%ld\n",
RMI_ABI_MAJOR_VERSION, RMI_ABI_MINOR_VERSION,
RMI_ABI_VERSION_GET_MAJOR(res.a1), RMI_ABI_VERSION_GET_MINOR(res.a1),
RMI_ABI_VERSION_GET_MAJOR(res.a2), RMI_ABI_VERSION_GET_MINOR(res.a2));
+ return -ENXIO;
+ }
+
+ kvm_info("RMI ABI version %d.%d\n", version_major, version_minor);
+
We probably need to print the requested version, instead of the lower implemented
version, if I'm correct. At present, both of them have been fixed to v1.0 and we
don't have a problem though.
kvm_info("RMI ABI version v%d.%d\n", RMI_ABI_MAJOR_VERSION, RMI_ABI_MINOR_VERSION);
+ return 0;
+}
+
Thanks,
Gavin
